Field of the Invention
This invention relates to improvements in a variable volume capture device. More particularly, the present variable volume capture device that allows for capture and delivery of a representative and exact volume of liquid for online (or at-line) chemical analysis. In particular, this is intended for use on the sampling and analysis of multiple sample sources.
Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Many industries today use chemical processing in, for example, mining, food processing, refining, water treatment, recycling, and semiconductor manufacture, metal and plastic surface treatment, and so on. In most cases, monitoring of the process chemistry by chemical analysis is necessary to maintain the product quality and consistency. For analysis in general and for online (or at-line) chemical analysis in particular, it is usually necessary to obtain a liquid sample and to dispense it accurately. For this it is important that the sample be representative of the whole and that the amount captured and dispensed be controlled. To obtain a representative sample, particularly when different sample sources and compositions are anticipated, it is necessary to remove completely and desirable to purge out efficiently old sample. And for reasons of both obtaining a representative sample and of dispensing a consistent and accurate volume of sample, it is necessary to remove air bubbles from the sample and sample chambers. In addition, a process with multiple analyses and corresponding multiple analytical procedures can benefit from a device or system that captures and delivers variable, selectable, but still accurate, sample volumes.
Historically, mechanized syringes and burettes have worked well for some of these analytical functions. That is, they can be operated to draw (fill) any amount within their range, and likewise precisely dispense a specific amount. The Kloehn (Las Vegas, Nev.) model V6 syringe and syringe drive, for example, perform these functions and can include a valve at the syringe tip to select fluid source and destination(s) as well. But as the syringe chamber is effectively a fluidic dead-end, this is not a flow-through device and consequently sample change-over is either inefficient or incomplete. Although one could orient the unit so that the syringe tip points downward to facilitate drainage, this would defeat the air-purging that is achieved in the normal, upward direction.
A number of patents and or publications have been made to address these issues. Exemplary examples of patents and or publication that try to address this/these problem(s) are identified and discussed below.
U.S. Pat. No. 6,235,002 issued May 22, 2001 to Edward Lawrence Carver, Jr et al. discloses a Syringe for Use in Fluid-Handling Apparatus. The syringe has a housing, a substantially fixed seal, a solid or closed-tip plunger, an internal passageway formed between the housing and the plunger, and at least two ports on the housing with at least one port located at each end of the passageway for the passage of fluids and the elimination of gas. While the syringe takes a sample, there can be a cross contamination and the sample is fixed in volume.
U.S. Patent publication Number 20080060413 was published on Mar. 13, 2008 to Masao Miyamoto et al., discloses a Flow Analysis System. The deaerator comprises a liquid-containing means variable in internal volume for containing the liquid together with gas bubbles included in the liquid. While the dearator can extract a sample, the dearator only extracts a sample from a flow and not from a standing pool.
U.S. Patent Publication Number 20140219311 was published by Valerian Plotnikov et al., discloses an Isothermal Titration Microcalorimeter Apparatus and Method of Use. This patent describes an automatic pipette assembly for an isothermal titration micro calorimetry system. The pipette system is basically a single use sampling system because when a sample is taken the syringe holder can be contaminated.
What is needed is a variable volume capture device that allows for a capturing and delivery of a representative and exact volume of liquid for chemical analysis.